This invention relates to a passenger conveyor system, such as an escalator and a moving walk, for transporting passengers, and more particurly to a driving unit for the passenger conveyor for providing an improved comfort of the passengers riding on the conveyor having a high lift or a long course.
At present, an escalator system, as a passenger conveyor system, can be roughly divided into two types according to the type of driving system used. One is a modular type escalator system, as shown in FIG. 1, in which a compact driving unit 1 is mounted in an inclined portion of the escalator for driving an endless step chain 2 for both an upper bearing run and a lower return run. The other is a sprocket wheel type escalator in which a driving unit 1a, as shown in FIG. 2, is disposed at an upper horizontal section of the escalator for driving a main sprocket wheel 1b which drives an endless step chain 2.
In the former modular type escalator system, many driving units can be provided according to need when extending the length of the escalator, thereby making the escalator system compact. However, since the steps on which the passengers are standing are directly driven by the driving unit 1, vibration of the unit 1 can be easily propagated to the passengers, resulting in the reduced comfort of the passengers standing on the steps. Furthermore, the steps must be disassembled when repairing of the driving unit and, accordingly the maintenance of the system is both time consuming and tedious.
On the other hand, with the latter sprocket wheel type conveyor system in which the main sprocket wheel 1a is used for driving the step chain 2, the comfort of the passengers is improved. However, this system necessitates a large driving unit for a higher rise, resulting in the necessity of larger space of a machine room disposed at a upper portion of the escalator system.
In order to deal with such problems, an escalator using a linear motor has been proposed. However, this necessitates the provision of a plurality of linear motors as well as the provision of a mechanical brake for braking the escalator system and, accordingly, results in a complicated and costly structure.